Commonly known as "point to point" navigation
Or, in ICAO Doc 8168 terms, "dead reckoning". If we are talking about instrument approaches designed to international standards, then that dead reckoning segment - i.e. the arrival segment, prior to the Initial Approach Fix - must be shown, e.g. as a Direct Arrival procedure. Otherwise, as you say Intruder, you just have to guess!
To see what I'm talking about take a look at the Dinard ADIDI VOR DME 17 procedure at:
http://www.sia.aviation-civile.gouv....D%202.LFRD.pdf
How does one find ADIDI or DIRGO? There is no procedure for how to get to either. Clearly the two IAFs are designed to give traffic from the north a shortened procedure so they don't have to go all the way to the DIN then out again, but if you're supposed to get there by flying a radial off something else, or a DME arc outside of either ADIDI or DIRGO followed by a turn at a lead radial, shouldn't that be shown?
NS
